The demonstration in our laboratory of net synthesis of certain phospholipids by retinal cellular fractions and the observation that the pigment epithelium contributes significantly to the enzyme activity of these cellular fractions have lead to experimental procedures designed to more completely characterize the enzymes and mechanisms involved in phospholipid synthesis in normal and dystrophic retinae and the mode by which these phospholipids are incorporated into rod outer segments and abnormal structures in dystrophic retinae. The proposed project is designed (1) to explore endogenous mechanisms by which phospholipid catabolism and anabolism are controlled in the retina, and (2) to determine the extent to which phospholipid synthesis in normal and dystrophic retinae can be controlled by diet and pharmacological agents known to effect lipid metabolism in other tissues. The results of the investigations will be related to previous work by others on the structure of normal and dystrophic retinae in an effort to understand and control types of human retinitis pigmentosa.